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The marathon may have marked the beginning of the trend for extreme exercise and new forms of extreme fitness routines are growing in popularity.

However, fans of the programs potentially risk serious health issues if they don’t take a simple precaution first, says new research from Mercy Health.

In research that appeared in the North American Journal of Medical Science (Volume 5, Issue 8, August 2013), Mercy Health Physician Charles J. Glueck, MD found that a severe vitamin D deficiency could place adherents of very high level exercise at greater risk for serious health issues. These issues include:
• Myositis/myopathy, or muscle disease, symptoms of which include muscle pain and an inability to move the muscles properly
• Rhabdomyolysis, in which the damaged muscles release myoglobin into the bloodstream, which damages kidneys, leading to acute kidney failure

“When an athlete who has very low level of vitamin D in the blood engages in very strenuous, high level exercise, he or she can damage the skeletal muscles enough to release their myoglobin protein into the blood stream and cause acute kidney failure or myopathy,” said Glueck.

Working with medical resident Brandon Conrad, Glueck recently reported rhabdomyolysis with acute kidney failure in an athlete during a footrace. Subsequently, physicians found that the athlete had very low serum vitamin D.

“I recommend that athletes taking on prolonged and strenuous exercise, such as a marathon or extreme fitness routine, have a blood test to measure their serum vitamin D levels. If the level is low, the athlete should hold off from major physical exertion until he or she has a normal level of vitamin D in the blood.”

Vitamin D is associated with bone health and muscle function. A normal Vitamin D level is 31 or more nanograms per milliliter (ng/mL). Dr. Glueck found that patients with an extreme deficiency of vitamin D (six ng/mL or less) experienced severe rhabdomyolysis and kidney failure.

“Men and women should ensure they have normal levels of vitamin D in their blood before heavy exertion,” said Glueck. “Vitamin D could perhaps prevent severe muscle damage and other events which may occur in previously asymptomatic athletes.”

“Athletes with a very low level of vitamin D in the blood who engage in strenuous exercise can damage the skeletal muscles enough to release myoglobin protein into the blood stream and cause acute kidney failure or myopathy,” says Dr. Glueck. “Athletes taking on prolonged, strenuous exercise should have a blood test to measure their serum vitamin D levels. If the level is low, the athlete should hold off from major physical exertion until he or she has a normal level of vitamin D in the blood.”